cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A143890 Number of ways of placing kings with no more than 4 mutual attacks on an n X n chessboard symmetric about both diagonal and antidiagonal.

Table of values

n a(n)
0 1
1 2
2 3
3 9
4 16
5 61
6 143
7 802
8 2265
9 17236
10 59156
11 631443
12 2686969
13 39237301
14 210001256

List of values

[1, 2, 3, 9, 16, 61, 143, 802, 2265, 17236, 59156, 631443, 2686969, 39237301, 210001256]